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Question
If 1 – cos2θ = `1/4`, then θ = ?
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Solution
1 – cos2θ = `1/4` ......[Given]
∴ sin2θ = `1/4` .....`[(because sin^2theta + cos^2theta = 1),(therefore 1 - cos^2theta = sin^2theta)]`
∴ sin θ = `1/2` ......[Taking square root of both sides]
∴ θ = 30° ......`[because sin 30^circ = 1/2]`
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